Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada.
Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy.
Scand J Med Sci Sports. 2020 Sep;30(9):1642-1654. doi: 10.1111/sms.13735. Epub 2020 Jun 17.
Compared to level running (LR), different strategies might be implemented by runners to cope with specific challenges of graded running at different speeds. The changes in joint kinetics and kinematics associated with graded running have been investigated, but their interactions with speed are unknown. Nineteen participants ran on an instrumented treadmill at five grades (0°, ±5° and ± 10°) and three speeds (2.50, 3.33 and 4.17 m/s), while 3D motion and forces were recorded. Three speed × five-grade repeated-measures ANOVA was used to analyze kinetic and kinematic variables. A speed × grade interaction was observed for hip range of motion (ROM). Downhill running (DR) at fastest speed did not reduce ROM at the hip, compared to LR. Compared to LR, it was observed that the hip joint was responsible for a greater contribution of energy generation while running at the fastest speed at +10°. Speed × grade interactions were also observed for the energy absorption, peak moment, and peak power at the knee. Contrary to LR, running faster during UR did not require higher peak power at the knee. Finally, DR at the fastest speed did not increase peak negative power at the knee compared to LR. This study demonstrates that ankle, knee, and hip joint kinetics depend on speed and grade of running, while the effect of grade on joint kinematics was not substantially modulated by speed.
与平地跑步（LR）相比，跑步者可能会采用不同的策略来应对不同速度的分级跑步的特定挑战。已经研究了与分级跑步相关的关节动力学和运动学的变化，但它们与速度的相互作用尚不清楚。19 名参与者在装有仪器的跑步机上以五个坡度（0°、±5°和±10°）和三个速度（2.50、3.33 和 4.17 m/s）进行跑步，同时记录了 3D 运动和力。使用三速×五坡度重复测量方差分析来分析动力学和运动学变量。观察到速度×坡度交互作用对髋关节运动范围（ROM）的影响。与 LR 相比，最快速度下的下坡跑步（DR）并没有减少髋关节的 ROM。与 LR 相比，在+10°的最快速度下，髋关节负责产生更大的能量贡献。在膝关节的能量吸收、峰值力矩和峰值功率方面也观察到速度×坡度的交互作用。与 LR 相反，在 UR 中更快地跑步并不需要更高的膝关节峰值功率。最后，与 LR 相比，最快速度下的 DR 并没有增加膝关节的峰值负功率。本研究表明，踝关节、膝关节和髋关节的动力学取决于跑步的速度和坡度，而坡度对关节运动学的影响并没有被速度明显调节。
